Manufacture of staple fiber yarns



June 4, 1935. w. l. TAYLOR ET AL MANUFACTURE OF STAPLE FIBER YARNS FiledJune 23, 1953 ATTORNEYS from staple fiber.

Patented June 4,"

PATENT OFFICE MANUFACTURE OF STAPLE FIBER YARNS William Ivan mm andLeslie Brisbane Gibbins, Spon'don; near Derby, England, aesigm' ore toCelanese Corporation of America, a corporation of Delaware Application15 Claims.

Thisinvention relates to the manufacture of textile materials, and inparticular to yarns having a basis of continuous filaments, buthavingthe appearance of spun yarn, that is yarn made In the manufacture ofspun yarn from artificial fibers, the usual practice is to cutcontinuous artificial filaments or waste filaments into comparativelyshort lengths, for example of 1 to 2 inches or more, and then subjectthe staple fibers produced to a series ofoperations appropriate to' thelength of the fiber, such operations being similar to those accorded tonatural fibers such as cotton or wool, including opening, carding,drawing and spinning. These operations represent considerable expense inthe production of such yarns, since they involve a relatively slowtransformation of the initial fibrous material to a finished yarn.

The object of the present invention is to produce yarn having anappearance similar to that of yarn made from spun fiber while avoidingthe necessity for forming continuous filaments into 'short lengths andspinning the fibers thus produced. The particular p rpose of theinvention is to enable a fairly close measure 'of' control to beobtained over the length of the fiber, so as to obtain aspun yarn asuniform as possible in structure," and consequently of. a fairly highdegree of strength. In its broadest aspect the invention comprises theconversion into fibrous yarns of continuous filament yarns the strengthof whose filaments is so modified that under the application of abreaking load, the filaments are broken or torn at fairly definitepoints. The fibrous mass thus produced is then twisted to bind thefibers together into a yarn similar to spun yarn. The points of breakageshould be at such distances apart along the length of the filaments, andso spaced apart between filament and filament along the length of theyarn, that the fibers produced by breakage of the several filamentsoverlap each other in the yarn.v 'I'his spacing of the points ofbreakage should be as even as possible, so that not only are fibers ofsubstantially-equal length produced, but also that substantiallyconstant overlap is obtained. Thus, for example, in a continuousfilament yarn containing 40 filaments a spacing of the points ofbreakage between filament and filament of approximately a twentieth ofan inch would enable fibers of approximately two inches in length tooverlap evenly and constantly throughout the length of the fibrous yamproduced.

The invention is applicable to the production June 23, 1933, Serial No.677,218 Great Britain Jilly 4, 1932 of fibrous yarns from all kinds ofcontinuous or substantially continuous filaments or mixtures, ofcontinuous filaments. Among artificial contin-. uous filament yarnswhich may be converted according to the invention may be mentionedcellulose acetate-or other organic derivatives of cellulose,'such asother cellulose esters, e. g., cellulose formate, propionate andbutyrate, and'cellulose ethers such as ethyl and benzyl cellulose, andviscose, nitro-cellulose, and cuprammonium 1o yam. e

The modification of the filament structure to bring about the fairlydefinite position of filament breakage may be ,efiected in various ways,con-' veniently by weakening the material of the'fila- 15 ments atinervals. If the filaments are rendered sufiiciently weak, breakage maybe effected without unduly extending the filaments as a whole, theextension taking place mainly at the weakened portions, so that theelasticity of the final 2o fibers may not be seriously reduced by theapplication of the breaking load. The material of the filaments may beweakened at intervals, for example, by bruising the filamentsmechanically, or by applying a liquid to the filaments having a-solventor softening or like weakening efifectu Instead of weakening thefilaments at intervals they may be treated with a size, except at theintervals at which they are desired to break, the intermittent coatingof size serving to reinforce the filaments over the greater part oftheir length.

After the strength of the filaments has been modified, they areconverted into staple lengths by passing them successively through twopairs of nipping rollers of which the second pair rotates fasterthan'the first, so 'as to draw out and break the filaments at the weakpoints. A twist tube or like device may be employed to impart falsetwist to the material leaving'the breaking device, 40

so as to give it sufiicient strength to maintain itself until a definitedegree has been imparted by the fiyer of the twisting spindle. Ifrequired supporting means may be provided between the .rollers of thebreaking device, such means con- 45 veniently comprising an endless bandor pair of bands driven at an appropriate linear speed,

Any desired number of yarns may be converted into fibers in a singlebreaking apparatus. Several filamentous yarns may be led side by side tothe apparatus and the fibers of these several threads may either bedrawn together into a single sliver ormay be maintained separate andseparately twisted into a roving on leaving the little or no staggeringof the weakened places is found. In this case, a number of such yarns orbundles is assembled together, either before, durmg, or after breakag sothat the fibers produced from the several yarns or bundles are evenlydistributed in the sliver. The slivers thus produced are twisted intorovings, and such rovings, or large rovings produced from large filamentbundles with distributed points of weakness may be subjected to drawingand further twisting until yarns are produced having the requisitedegree of fineness and strength. After breakage, the fibrous bundle maybe passed directly through draw rollers to reduce the size of thebundle, in which case the final yarn may be produced in the onecontinuous operation. Two or more twisted yarns may be doubled togetherat any drawing stage to increase the evenness and strength of thefinalyarn.

In order to improve the spinning properties of the fibers, which havethe smoothness of the filaments from which they are produced, rougheningmedia ,may be applied to increase the adhesion between the fibers.In'view of the importance of maintaining the even arrangement of thefibers in the sliver-like mass produced by breaking the filaments, it isdesirable that any such media should be applied to the filaments beforebreaking. Such media may be of an insoluble type, e. g. kieselguhr,talc, pumice, carborundum, and emery, and may be applied dry or aspastes or suspensions at any suitable stage prior to breaking, e. g.continuously with the production of artificial filaments. Solublematerials in crystalline or powder form may also be applied dry. Solublemedia may also be used, conveniently being applied as solutions of highconcentration, as described in U. S. application S. No. 585,381 filed7th January, 1932, so that drying can be economically effected to leavethe desired amount of roughening media on the fibers.

Where the materials are subject to electrification, as for example inthe case of cellulose acetate or other organic derivatives of cellulose,hygroscopic materials may be applied to the materials. For example,hygroscopic bodies may be applied as described in U. S. application S.No. 614,853 filed 1st June, 1932, the filaments preferably being driedbefore breaking.

By way of example some methods of carrying out the invention will now bedescribed in greater detail with reference to the accompanying drawingin which:--

Figure 1 is a perspective view of a form of apparatus for bruising thefilaments at intervals in order to facilitate their breakage;

Figure 2 is a perspective view of a form of breaking apparatus which maybe employed for converting the bruised filaments into fibers;

Figure 3 is another form of apparatus for bruising the filaments;

Figure 4 shows a further form of apparatus for weakening the filamentsat intervals; and

Figure 5 shows a form of apparatus for modifying the strength of thefilaments without weakening them.

Referring to Figure 1, a number of threads 5 each consisting of a numberof continuous filaments, are drawn over the ends of bobbins 6 and over aguide bar I and are passed between a pair of rollers 8, 9. The bobbins 6are sufiiciently large to enable the apparatus to continue in operationfor long periods without interruption. The lower roller 8 is driven bymeans of a pulley l and belt II. The upper roller 9. is driven by itsengagement with the roller 8. The roller 9 is provided with teeth l2helically disposed on the cylindrical surface thereof, and the roller 8is provided with recesses l3 adapted to engage with the teeth l2. Theroller 9 is pressed downwardly on the roller 8 by means of a stirrup land screw l6, so that pressure between the rollers may be adjustable. Atthe same time a braking device .11 is provided, acting on the upperroller 9 in order to cause the faces of the teeth I2 to coact with thesides of the recesses I3.

The threads of filaments 5 are spread out by a comb 48 so as to beengaged by different teeth l2 and recesses l3, and in passing betweenthe rollers 8, 9 the filaments of the threads 5 are bruised at intervalscorresponding to the circumference of the rollers 9, 9 and the number ofhelices of teeth or of recesses provided thereon. The bruised portionsof the threads 5 are indicated at l9, and it will be seen that thepositions of the bruises are staggered as between the different threads.The threads 5 after passing through guides 28 on a polished metal guideplate 2| are collected together by a further guide 22 and aresubsequently led by means of a traverse guide 23 on to a rotating bobbin24 by means of which they are collected.

In Figure 2, means are illustrated for effecting the breakage of thefilaments into fibrous lengths. The thread of bruised filaments 25 mayeither be drawn from a bobbin such as the bobbin 24 in Figure 1, or maybe drawn directly from the guide 2| of the apparatus illustrated inFigure 1. The latter method, when it is possible, avoids theinconvenience of storing the bobbins 24, reducing the possibility ofundesired breakage of the filaments in transport or storage. The thread25 is conducted successively between two pairs of rollers 26, 21 whichare preferably smooth surfaced, and covered with rubber, so as to nipthe thread. The distance between the rollers 26, 21'slightly exceeds theinterval between successive points of bruising on the filaments 25. Therollers 21 are driven at a higher peripheral speed than the rollers 26so that the filaments are stretched between the rollers, and, as aresult of their previous weakening, readily break at the points wheresuch weakening has been efiected. Since weakening has been effected atregular intervals along the filaments of the thread 25, the filamentsare broken into staple lengths of substantially uniform size. At thesame time since the different filaments of the thread 25 have beenweakened at different points, the thread 25 is not broken as a whole,and issues as a uniform and continuous thread 28 of staple fibers readyto be collected on a flier spinning apparatus 29 where it is twisted andwound on to a bobbin 30. The twist inserted by the flier 29 into thecontinuous thread 28 gives it suflicient cohesion to stand up to anysubsequent spinning operation to which it may be subjected.

In Figure 3 a pair of rollers 32, 33 is illustrated which may be used inplace of the rollers 8, 9 shown in Figure l. The roller 33 is providedwith one ormore upstanding helical ridges 34 engaging with a number ofhelical grooves 35 in the rollers 32. The ridges 34 and the groove 35co-operate to bruise the filaments of the threads 5 at intervals, in amanner similar to that described with reference to Figure 1. Instead ofarranging the filaments as a number of threads of filaments as in Figure1, the filaments are evenly spread out into a sheet 31, by means of areed 38, so that the points of bruising are more evenly distributedthroughout the whole bundle of bruised filaments.

In Figure 4, a number of filaments in the form of a fiat sheet 31, iscaused to pass from a reed 38 under a cranked portion 39 of a rotatingshaft 40. The filaments then pass over a wick 4|, dipping into a vessel42 containing a liquid adapted to soften or weaken the substance of thefilaments. The wick 4| is disposed obliquely across the sheet offilaments 31, so that the points of weakening of the different filamentsare differently disposed along the length of the sheet 31. The level ofthe wick 4| and the level of the shaft 40 are so arranged that the timeduring which the filaments are pressed down into contact with the wickis short, so that the filaments are only weakened over a relativelysmall part of their length. The sheet of filaments 31 may either becollected on a bobbin, as described with reference to Figure l, or maybe conducted directly to breaking rollers, as described with referenceto Figure 2.

The liquid applied by the wick 4| may be a solvent or softening agent,or in the case of cellulose ester filaments, it may be a saponifyingagent. As examples of suitable solvent or softening materials for use inconnection with filaments of cellulose acetate, acetone, a mixture ofacetone and thiocyanate, acetic acid, lactic acid, formic acid,1.4-oxanone, tetrachlorethane, chloroform, ethyl acetate, phenol, oraniline may be used, preferably at a strength which merely brings aboutweakening of the filaments without rendering them unduly soft and liableto stick to each other. Thus, for example, a dilute solution of acetoneand water may be employed. Water may also be employed as a weakeningagent, thus utilizing the reduction in tenacity found in wettingartificial filaments as a means for securing breakage at predeterminedpoints.

Instead of a solvent or softening liquid, a saponifying agent may beemployed in connection with cellulose ester filaments, in the mannerdescribed for example in U. S. application S. No. 415,803 filed 21stDecember, 1929. Such saponification may be complete, or may result onlyin such partial conversion of the cellulose ester that the loss involume brings about a sufiicient weakening of the filaments to ensuretheir breakage at the parts saponified. Where saponification has takenplace, the filaments are capable of receiving differential coloureffects, so that the ends of the fibers may be coloured differently fromthe body of the fibers, thus enabling a mixed colour effect to beobtained in the spun yarn. Where, however, the saponification is onlypartial, level dyeing may be effected, since the partially saponifiedcellulose ester retains its affinity for the usual dyestuffs.

The apparatus shown in Figure 4 may be employed with slight modificationfor the application of a size, to strengthen the filaments except overshort lengths occurring at regular and frequent intervals. A better formof apparatus for the purpose however is illustrated in Figure 5. In thisfigure, a sheet of filaments 31 proceeding from a reed 38 pass over andin contact with a drum or roller 45, which dips into a trough 46containing the size' to be applied. Deep helical grooves 41 in thesurface of the roller 45 prevent the application of size at pointsoccurring at intervals along the filaments, and owing to the helicalnature of the grooves 41, the points of non-application are differentlydisposed on the different filaments of the sheet 31. By the provision ofa helical ridge instead of a helical groove, the apparatus may beemployed for the application of a solvent or a saponifying agent.

Where a size or a saponifying agent is applied, so that some time isneeded, either for drying of the size, or for the working of thesaponifying agent, it is preferred to collect the filaments on a bobbinand to break them in a separate step.

Where a volatile and rapidly acting solvent material is applied however,it is preferred to conduct the filaments directly to the breakingapparatus before the solvent material has time to evaporate from thefilaments, so that the full effect of the weakening can be utilized.

What we claim and desire to secure by Letters Patent is:-

1. Process for the production of spun yarns from continuous filaments,said process comprising modifying the strength of a plurality ofassociated continuous filaments at intervals, different filaments beingso treated at diiferent points along their length, applying tensioncontinuously along a bundle of such filaments until they break atintervals corresponding to the spacing of the modified portions, sotransforming the filaments into a continuous bundle of staple fibers,and spinning the staple fibers so produced into a spun yarn.

2. Process for the production of spun yarns from continuous filaments,which comprises weakening a plurality of associated continuous filamentsat intervals, different filaments being weakened at different pointsalong their length, applying tension continuously along a bundle of suchfilaments until they break at intervals corresponding to the spacing ofthe weakened portions, so transforming the filaments into a continuousbundle of staple fibers, and spinning the staple fibers so produced intoa spun yarn.

3. Process for the production of spun yarns from continuous elements,which comprises bruising a plurality of associated continuous filamentsat intervals, different filaments being bruised at different pointsalong their length, applying tension continuously along a bundle of suchfilaments until they break at intervals corresponding to the spacing ofthe bruised portions, so transforming the filaments into a con tinuousbundle of staple fibers, and spinning the staple fibers so produced intoa spun yarn.

4. Process for the production of spun yarns from continuous filaments,which comprises applying a softening agent to a plurality of associatedcontinuous filaments at intervals, different filaments being softened atdifierent points along their length, applying tension continuously alonga bundle of such filaments until they break at intervals correspondingto the spacing of the softened portions so transforming the filamentsinto a continuous bundle of staple fibers, and spinning the staplefibers so produced into a spun yarn.

.5. Process for the production of spun yarns from continuous cellulosederivative filaments, which comprises modifying the strength of aplurality of associated continuous cellulose derivative filaments atintervals, different filaments being so treated at different pointsalong their length, applying tension continuously along a bundle of suchfilaments until they break at intervals corresponding to the spacing ofthe modified portions, so transforming the filaments into a continuousbundle of staple fibers; and spinning the staple fibers so produced intoa spun yarn.

6. Process for the production of spun yarns from continuous celluloseacetate filaments, which comprises modifying the strength of a pluralityof associated continuous cellulose acetate filaments at intervals,different filaments being so treated at different points along theirlength, applying tension continuously along a bundle of such filamentsuntil they break at intervals corresponding to the spacing of themodified portions, so transforming the filaments into a continuousbundle of staple fibers, and spinning the staple fibers so produced intoa spun yarn.

7. Process for the production of spun yarns from continuous celluloseester filaments, which comprises applying a saponifying agent to aplurality of associated continuous cellulose ester filaments atintervals along their length so as to weaken them, different filamentsbeing so'weakened at different points along their length, applyingtension continuously along a bundle of such filaments until they breakat intervals corresponding to the spacing of the weakened portions, sotransforming the filaments into a continuous bundle of staple fibers,and spinning the staple fibers so produced into a spun yarn.

8. Process for the production of spun yarns from continuous filaments,which comprises weakening a plurality of associated continuous filamentsat intervals, different filaments being weakened at different pointsalong their length, applying tension continuously with such weakeningalong a bundle of such filaments until they break at intervalscorresponding to the spacing of the weakened portions, so transformingthe filaments into a continuous bundle of staple fibers, and spinningthe staple fibers so produced into a spun yarn.

9. Process for the production of spun yarns from continuous filaments,said process comprising modifying the strength of a plurality ofassociated continuous filaments at intervals, different filaments beingso treated at different points along their length, applying tensioncontinuously along a bundle of such filaments until they break atintervals corresponding to the spacing of the modified portions, sotransforming the filaments into a" continuous bundle of staple fibers,twisting such bundle of staple fibers into a sliver continuously withsuch breaking, and spinning the twisted product into a spun yarn.

10. Process for the production of spun yarns from continuous filaments,said process comprising weakening a plurality of associated continuousfilaments at intervals, different filaments being so treated atdifferent points along their length, applying tension continuously withsuch weakening along a bundle of such filaments until they break atintervals corresponding to the spacing of the weakened portions, sotransforming the filaments into a continuous bundle of staple fibers,twisting such bundle of staple fibers into a sliver continuously withsuch breaking, and spinning the twisted product into a spun yarn.

11. Apparatus for facilitating the breaking of continuous filaments intosubstantially uniform staple lengths, said apparatus comprising meansfor distributing a plurality of travelling continuous filaments in theform of a sheet, and means for modifying the strength of the travellingfilaments at intervals along their length, said means being adapted toeffect such modification at points on different, filaments which aredifferently distributed along the length of said sheet.

12. Apparatus for facilitating the breaking of continuous filaments intosubstantially uniform staple lengths, said apparatus comprising meansfor distributing a plurality of travelling continuous filaments in theform of a sheet of individual filaments, and means for modifying thestrength of the travelling filaments at intervals along their length,said means being adapted to effect such modification at points -ondifferent filaments which are obliquely distributed across said sheet.

13. Apparatus for facilitating the breaking of continuous filaments intosubstantially uniform staple lengths, said apparatus comprising meansfor distributing a plurality of travelling continuous filaments in theform of a sheet, and means for bruising the travelling filaments atintervals along their length, said means being adapted to effect suchbruising at points on different filaments which are differentlydistributed along the length of said sheet.

14. Apparatus for facilitating the breaking of continuous filaments intosubstantially uniform staple lengths, said apparatus comprising meansfor distributing a plurality of travelling continu- Ous filaments in theform of a sheet of individual filaments, a pair of rollers between whichsaid sheet is caused to pass, and inter-engaging helical grooves andridges disposed on said rollers, adapted to bruise the travellingfilaments at intervals along their length, said rollers being adapted toeffect such bruising at points on the different filaments which areobliquely distributed across said sheet.

15. Apparatus for facilitating the breaking of continuous filaments intosubstantially uniform staple lengths, said apparatus comprising meansfor distributing a'plurality of travelling continuous filaments in theform of a sheet of groups of filaments, a pair of rollers between whichsaid sheet is caused to pass and inter-engaging teeth and recesseshelically disposed on said rollers adapted to bruise the travellingfilaments at intervals along their length, said rollers being therebyadapted to effect such bruising at points on different filaments whichare differently distributed along the length of said sheet.

WILLIAM IVAN TAYLOR. LESLIE BRISBANE GIBBINS.

